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Why tint for night driving ?

I know people want tints for night driving. Mainly yellow. WHY!!! I am of the opinion and impression that ANY tint at all will ultimately dull visibility. Am I not correct in this? If I am not, then tell me why exactly yellow is so great and will increase and decrease visibility at night? I need to know more on this subject after all these years.

Yellow tint mainly to enhance the contrast.. to be precise, it is not advice to use it at normal night driving.. depend on the environment condition.. use it during foggy condition will surely help due to the poor contrast environment causing by the fog. drive at night on the well lighten up city street is really a bad idea to use the yellow tint.

I used to work in a clinic where the Dr's (MD's) would prescribe that for nearly all their post-Lasik patients, with the expectation that they were going to have halo effects after surgery. Anything the Dr. says, the patient will take as gospel.

So what does this exactly mean? That when the pupil is fully open (dilated) is allows all light in and increased light of the "blue" spectrum and the yellow supposed to combat this or people perceive it too?

Also, bear in mind that the vast majority of people who think they want this yellow "night driving" tint are seniors. They have already lost as much as 2/3 of their contrast sensitivity they had when they were in their teens and 20's. You want to reduce that even further...why??

Just keep me the hell off the sidewalks when they're out driving please! :shiner:

See, there are two ways of increasing contrast for the human vision system:

You can reduce the "black" end, i.e., make darker, or

You can increase the "white" end, i.e., make brighter.

Yellow tints, of the proper density, may reduce overall light, but the human eye's response is not linear, especially with respect to color wavelength. So yellow may reduce peak white sensitivity (i.e., glare) less, than it makes the black (dark) areas at night seem blacker.

Voila - More "perceived" contrast and less glare.

Those who are videophiles know where I'm taking this discussion, but I am open to other thoughts from anyone here.

Its really the eyes

While 'tis true that any tint will decrease the available light, that doesn't take peoples' psychology into effect. We know that a lens in yellow will highlight the peak of the eye's spectral response curve. It will also decrease the amount of blue light that is bouncing around our visual targets and periphery, reducing this glare component. When we are younger this is fairly unimportant. But when we are dealling with the geriatric crowd this becomes more of an issue. It is probable that a very light tint in yellow will help these drivers on urban roads (basically where they mostly live, anyway) by icreasing their contrast sensitivity. Of course, any tint used at night on rural, unlit roads is a no-no! The major help for all of our patients, young and old, is to make sure that the inside of the windshield is ablolutely, spotlessly clean and streak free.

Thanks Barry,
My post exactly. If any tint reduced contrast then wearing sunglasses for driving would be stupid. Most contrast tests are done on white and black, not in mutli-color, so they may not represent real life senarios. I have a copy of a study done in Australia by the governmet (highest sunglass requirements in the world) that shows that in a chart with blue letters, yellow lenses improve tested contrast over no lenses.

I used to live in the formally very foggy California Central Valley (global warming and drought have reduced the fog in recent years), and it would be so thick that you could open your car door and barely see the white line on the side of the road. I made tons of special lenses for the California Highway Patrol for these white-out conditions. I used a Brown Polar A, added both Yellow and Red tint to make it Orange and added A/R. Ugly, but you could see up to 20 times farther in the fog. The Highway Patrol was almost lined up outside my office. Its strange when 10 cops in uniform walk in and ask for you, let me tell you.

My net forumula is: when blue light conditions exist, reducing that blue light at a faster rate than other spectrums will improve contrast even with a darker lens. The above lens had a final LT of only 45%, yet contrast increased almost 10 fold. You could make out objects that were otherwise invisable.

Anyone remember the old pre-Luxottica Revo's when the lenses were made by Coherant? Incredible contrast. If anyone Skis, you know how a terrible those mogols you can't see are are, you hit them like you never saw them. Well, in glare/blue light conditions contrast drops to almost zero. I tested many lenses in these conditions and Revo's brought out the most detail.

It doesnt make any sense to say that any tint reduces contrast, and then put on sunglasses. Contrast tests need to be done in color to be fully accurate of real life conditions.

Do your own tests on snow in the sun with Amber lenses, gray lenses, no lenses in both polarized and non-polarized. Look for the most detail. I guarantee you will see more detail (ie contrast) with the Amber Polarized lens than anything else. Blame the shortwave blue, and enjoy the rest of the day with your new sunglasses.

Originally Posted by Barry Santini

See, there are two ways of increasing contrast for the human vision system:

You can reduce the "black" end, i.e., make darker, or

You can increase the "white" end, i.e., make brighter.

Yellow tints, of the proper density, may reduce overall light, but the human eye's response is not linear, especially with respect to color wavelength. So yellow may reduce peak white sensitivity (i.e., glare) less, than it makes the black (dark) areas at night seem blacker.

Voila - More "perceived" contrast and less glare.

Those who are videophiles know where I'm taking this discussion, but I am open to other thoughts from anyone here.

Discussion?

Barry

Beer is proof that God loves us and wants us to be happy ~Benjamin Franklin

However, the original poster querried specifically regarding night driving. Short wave blue radiation is a non factor given the daylight scenario's you're suggesting. And while I would personally agree that a brown base (and to a lesser extent rose) offers what I personally feel to be greatly enhanced vision in daylight (and I SO know what you mean about the good ol' REAL Rēvo's from back in the day!), the night driving equation is very very different.

Anyone remember the old pre-Luxottica Revo's when the lenses were made by Coherant? Incredible contrast. If anyone Skis, you know how a terrible those mogols you can't see are are, you hit them like you never saw them. Well, in glare/blue light conditions contrast drops to almost zero. I tested many lenses in these conditions and Revo's brought out the most detail.

Those lenses used a multilayer coating system to produce destructive interference (kind of like A/R only different); they could contour the filtration curve beautifully. Talk about residual color! I liked the orange best. Even with Revo's, a grey lens on snow on an overcast day would have you eating your knees.

Rēvo never actually *made* a grey lens however to the best of my knowledge. Did they? A sort of G-15 in their old Traveler series was the closest I ever recall. Have you seen what Mitch is up to these days? Pretty cool stuff - almost out of Back to the Future!

A shame the Oakley vultures had to come along and poison both the frame AND lens designs. Way to go Lux. Kinda like ripping out the hand stitched leather seat of a pristine '39 Rolls just to wipe one's nether regions after a large meal of chili and cabbage. It just should never have been done!

should tints be used

Visual responses in low illuminance are not as simple as just increasing lens transmission. It affects Rx (usually a myopic shift - although some people become hyperopic), magnocellular processing, contrast sensitivity and 3rd order aberrations.

These should ALL be addressed by optical professionals - sadly they are usually ignored.

As for tints - why yellow? I wear a specific (not quite yellow) tint for night driving ( together with a lens specification which takes into account all other effects) - the difference in acuity, contrast sensitivity, edge and movement detection is remarkable. "Starring" of headlights (a columnated light source) is eliminated, ability to see in the distance is enhanced and my safety is much greater.

Whilst the obvious answer is to increase transmission at night - it is often poor advice. In fact here in the UK it can be a criminal offence to drive with tinted glases. That leaves me in a profesional dilemma - to give people measurably better vision - or to comply with a law which can be shown to be wrong!

Oh - and I do have the instrumentation to test for these effects - so I can say with confidence that the effects are not imagined.

Here we have a very strong opinion without any explanations on why and how. Basically just the old hat of promoting AR.

Originally Posted by Ian Jordan

These should ALL be addressed by optical professionals - sadly they are usually ignored.

As for tints - why yellow? I wear a specific (not quite yellow) tint for night driving ( together with a lens specification which takes into account all other effects) - the difference in acuity, contrast sensitivity, edge and movement detection is remarkable. "Starring" of headlights (a columnated light source) is eliminated, ability to see in the distance is enhanced and my safety is much greater. .................

Oh - and I do have the instrumentation to test for these effects - so I can say with confidence that the effects are not imagined.

I am your honour guilty of wanting to see better!

Here is the opposite opinion with a lot of backup, like years of research and experience. I would suggest you to look at the following 2 websites to see which statement has more validity. Ian Jordan is a well known research optician.

Tinted windshields are never tinted in a drivers line of sight! ANY tint on a spectacle lens reduces the amount of light able to pass through the lens. Obviously this does not refer to AR treated lenses which let in more light than untreated clear lenses.

I am reminded of the notice I received last year from the USGA regarding a new "Leaf" rule for lost golf balls during the fall season. (For those of you who may not be aware, your golf ball can become lost in or under the leaves) Anyway, the USGA provided a link to the page containing the "new leaf rule". When you clicked on it, you got the message

"There is no leaf rule"

I say the same thing about tinted lenses for night driving.
There is no tint for night driving!

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forget bedroom rule.................

Originally Posted by hcjilson

I am reminded of the notice I received last year from the USGA regarding a new "Leaf" rule for lost golf balls during the fall season. (For those of you who may not be aware, your golf ball can become lost in or under the leaves) Anyway, the USGA provided a link to the page containing the "new leaf rule".

I wish they had not forgotten to also make a bedroom rule, where these golf balls can end up year round and not only in fall. One just missed this morning and hit the shutter. :D